How this calculator works
A 401(k) is an employer-sponsored retirement account funded by a percentage of your salary, often with an employer match. This calculator projects the account balance forward using a month-by-month simulation, so it correctly handles an employer match that only applies up to a certain percentage of your salary.
Enter your current balance, salary, contribution percentage, the employer match terms, an expected annual return, and the number of years until retirement. The year-by-year table separates the balance into what you contributed, what your employer matched, and investment growth, so you can see exactly where the final number comes from.
Employer 401(k) matches are typically described as 'X% of your contribution, up to Y% of salary.' That means the employer only matches the contribution dollars up to the limit; contributing more than the limit still grows your own balance, it just is not matched further. Annual IRS contribution limits also apply to 401(k) plans and change periodically, so check the current limit for your plan year rather than assuming a fixed number.
The formula
Employee monthly contribution: (annual salary ÷ 12) × contribution %Matched contribution %: min(contribution %, match limit %)Employer monthly match: (annual salary ÷ 12) × matched contribution % × match %Balance grows monthly: balance = balance × (1 + r/12) + (employee + employer monthly deposit)r is the expected annual return as a decimal. The employer match formula caps at the match limit — contributing beyond it adds to your own balance but not to the match.
Worked example: $10,000 balance, $60,000 salary, 6% contribution
- Monthly salary is $60,000 ÷ 12 = $5,000. At a 6% contribution rate, you deposit $300 per month.
- The plan matches 50% of your contribution up to 6% of salary. Since 6% is exactly the match limit, the employer matches all of it: 50% × $300 = $150 per month.
- Combined monthly deposit is $450, starting from a $10,000 balance, growing at 7% annually compounded monthly for 30 years.
- The projected balance reaches about $630,152: roughly $108,000 from your own contributions, $54,000 from the employer match, and the remaining $458,000 from investment growth.
Frequently asked questions
What does 'match up to 6% of salary' mean?
It means the employer only matches contributions on the first 6% of your salary that you contribute. If you contribute 10% of your salary, the employer still only matches based on the first 6 percentage points, not the full 10%.
Should I contribute at least enough to get the full match?
Most financial guidance treats the full employer match as part of your compensation, since it is money the employer adds only when you contribute. Contributing at least up to the match limit captures that match before considering any additional retirement savings.
Are there limits on how much I can contribute to a 401(k)?
Yes. The IRS sets an annual dollar limit on employee 401(k) contributions (with a higher limit for catch-up contributions at older ages), and these limits change from year to year, so check the current-year limit rather than relying on a fixed figure.
Does this calculator account for taxes?
No. It projects the account balance before any taxes or penalties that may apply on withdrawal, which depend on whether the account is traditional or Roth and on your situation at withdrawal.
Does the calculator assume my salary stays the same?
Yes, for simplicity it assumes a constant salary and contribution rate. Raises, bonuses, or contribution changes over time will change your actual results.